block/curl.c

   1 /*
   2  * QEMU Block driver for CURL images
   3  *
   4  * Copyright (c) 2009 Alexander Graf <agraf@suse.de>
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24
  25 #include "qemu/osdep.h"
  26 #include "qapi/error.h"
  27 #include "qemu/error-report.h"
  28 #include "qemu/module.h"
  29 #include "qemu/option.h"
  30 #include "block/block_int.h"
  31 #include "qapi/qmp/qdict.h"
  32 #include "qapi/qmp/qstring.h"
  33 #include "crypto/secret.h"
  34 #include <curl/curl.h>
  35 #include "qemu/cutils.h"
  36 #include "trace.h"
  37
  38 // #define DEBUG_VERBOSE
  39
  40 #define PROTOCOLS (CURLPROTO_HTTP | CURLPROTO_HTTPS | \
  41                    CURLPROTO_FTP | CURLPROTO_FTPS)
  42
  43 #define CURL_NUM_STATES 8
  44 #define CURL_NUM_ACB    8
  45 #define CURL_TIMEOUT_MAX 10000
  46
  47 #define CURL_BLOCK_OPT_URL       "url"
  48 #define CURL_BLOCK_OPT_READAHEAD "readahead"
  49 #define CURL_BLOCK_OPT_SSLVERIFY "sslverify"
  50 #define CURL_BLOCK_OPT_TIMEOUT "timeout"
  51 #define CURL_BLOCK_OPT_COOKIE    "cookie"
  52 #define CURL_BLOCK_OPT_COOKIE_SECRET "cookie-secret"
  53 #define CURL_BLOCK_OPT_USERNAME "username"
  54 #define CURL_BLOCK_OPT_PASSWORD_SECRET "password-secret"
  55 #define CURL_BLOCK_OPT_PROXY_USERNAME "proxy-username"
  56 #define CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET "proxy-password-secret"
  57
  58 #define CURL_BLOCK_OPT_READAHEAD_DEFAULT (256 * 1024)
  59 #define CURL_BLOCK_OPT_SSLVERIFY_DEFAULT true
  60 #define CURL_BLOCK_OPT_TIMEOUT_DEFAULT 5
  61
  62 struct BDRVCURLState;
  63 struct CURLState;
  64
  65 static bool libcurl_initialized;
  66
  67 typedef struct CURLAIOCB {
  68     Coroutine *co;
  69     QEMUIOVector *qiov;
  70
  71     uint64_t offset;
  72     uint64_t bytes;
  73     int ret;
  74
  75     size_t start;
  76     size_t end;
  77 } CURLAIOCB;
  78
  79 typedef struct CURLSocket {
  80     int fd;
  81     struct BDRVCURLState *s;
  82 } CURLSocket;
  83
  84 typedef struct CURLState
  85 {
  86     struct BDRVCURLState *s;
  87     CURLAIOCB *acb[CURL_NUM_ACB];
  88     CURL *curl;
  89     char *orig_buf;
  90     uint64_t buf_start;
  91     size_t buf_off;
  92     size_t buf_len;
  93     char range[128];
  94     char errmsg[CURL_ERROR_SIZE];
  95     char in_use;
  96 } CURLState;
  97
  98 typedef struct BDRVCURLState {
  99     CURLM *multi;
 100     QEMUTimer timer;
 101     uint64_t len;
 102     CURLState states[CURL_NUM_STATES];
 103     GHashTable *sockets; /* GINT_TO_POINTER(fd) -> socket */
 104     char *url;
 105     size_t readahead_size;
 106     bool sslverify;
 107     uint64_t timeout;
 108     char *cookie;
 109     bool accept_range;
 110     AioContext *aio_context;
 111     QemuMutex mutex;
 112     CoQueue free_state_waitq;
 113     char *username;
 114     char *password;
 115     char *proxyusername;
 116     char *proxypassword;
 117 } BDRVCURLState;
 118
 119 static void curl_clean_state(CURLState *s);
 120 static void curl_multi_do(void *arg);
 121
 122 static gboolean curl_drop_socket(void *key, void *value, void *opaque)
 123 {
 124     CURLSocket *socket = value;
 125     BDRVCURLState *s = socket->s;
 126
 127     aio_set_fd_handler(s->aio_context, socket->fd, false,
 128                        NULL, NULL, NULL, NULL, NULL);
 129     return true;
 130 }
 131
 132 static void curl_drop_all_sockets(GHashTable *sockets)
 133 {
 134     g_hash_table_foreach_remove(sockets, curl_drop_socket, NULL);
 135 }
 136
 137 /* Called from curl_multi_do_locked, with s->mutex held.  */
 138 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
 139 {
 140     BDRVCURLState *s = opaque;
 141
 142     trace_curl_timer_cb(timeout_ms);
 143     if (timeout_ms == -1) {
 144         timer_del(&s->timer);
 145     } else {
 146         int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000;
 147         timer_mod(&s->timer,
 148                   qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns);
 149     }
 150     return 0;
 151 }
 152
 153 /* Called from curl_multi_do_locked, with s->mutex held.  */
 154 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
 155                         void *userp, void *sp)
 156 {
 157     BDRVCURLState *s;
 158     CURLState *state = NULL;
 159     CURLSocket *socket;
 160
 161     curl_easy_getinfo(curl, CURLINFO_PRIVATE, (char **)&state);
 162     s = state->s;
 163
 164     socket = g_hash_table_lookup(s->sockets, GINT_TO_POINTER(fd));
 165     if (!socket) {
 166         socket = g_new0(CURLSocket, 1);
 167         socket->fd = fd;
 168         socket->s = s;
 169         g_hash_table_insert(s->sockets, GINT_TO_POINTER(fd), socket);
 170     }
 171
 172     trace_curl_sock_cb(action, (int)fd);
 173     switch (action) {
 174         case CURL_POLL_IN:
 175             aio_set_fd_handler(s->aio_context, fd, false,
 176                                curl_multi_do, NULL, NULL, NULL, socket);
 177             break;
 178         case CURL_POLL_OUT:
 179             aio_set_fd_handler(s->aio_context, fd, false,
 180                                NULL, curl_multi_do, NULL, NULL, socket);
 181             break;
 182         case CURL_POLL_INOUT:
 183             aio_set_fd_handler(s->aio_context, fd, false,
 184                                curl_multi_do, curl_multi_do,
 185                                NULL, NULL, socket);
 186             break;
 187         case CURL_POLL_REMOVE:
 188             aio_set_fd_handler(s->aio_context, fd, false,
 189                                NULL, NULL, NULL, NULL, NULL);
 190             break;
 191     }
 192
 193     if (action == CURL_POLL_REMOVE) {
 194         g_hash_table_remove(s->sockets, GINT_TO_POINTER(fd));
 195     }
 196
 197     return 0;
 198 }
 199
 200 /* Called from curl_multi_do_locked, with s->mutex held.  */
 201 static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 202 {
 203     BDRVCURLState *s = opaque;
 204     size_t realsize = size * nmemb;
 205     const char *header = (char *)ptr;
 206     const char *end = header + realsize;
 207     const char *accept_ranges = "accept-ranges:";
 208     const char *bytes = "bytes";
 209
 210     if (realsize >= strlen(accept_ranges)
 211         && g_ascii_strncasecmp(header, accept_ranges,
 212                                strlen(accept_ranges)) == 0) {
 213
 214         char *p = strchr(header, ':') + 1;
 215
 216         /* Skip whitespace between the header name and value. */
 217         while (p < end && *p && g_ascii_isspace(*p)) {
 218             p++;
 219         }
 220
 221         if (end - p >= strlen(bytes)
 222             && strncmp(p, bytes, strlen(bytes)) == 0) {
 223
 224             /* Check that there is nothing but whitespace after the value. */
 225             p += strlen(bytes);
 226             while (p < end && *p && g_ascii_isspace(*p)) {
 227                 p++;
 228             }
 229
 230             if (p == end || !*p) {
 231                 s->accept_range = true;
 232             }
 233         }
 234     }
 235
 236     return realsize;
 237 }
 238
 239 /* Called from curl_multi_do_locked, with s->mutex held.  */
 240 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 241 {
 242     CURLState *s = ((CURLState*)opaque);
 243     size_t realsize = size * nmemb;
 244
 245     trace_curl_read_cb(realsize);
 246
 247     if (!s || !s->orig_buf) {
 248         goto read_end;
 249     }
 250
 251     if (s->buf_off >= s->buf_len) {
 252         /* buffer full, read nothing */
 253         goto read_end;
 254     }
 255     realsize = MIN(realsize, s->buf_len - s->buf_off);
 256     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
 257     s->buf_off += realsize;
 258
 259 read_end:
 260     /* curl will error out if we do not return this value */
 261     return size * nmemb;
 262 }
 263
 264 /* Called with s->mutex held.  */
 265 static bool curl_find_buf(BDRVCURLState *s, uint64_t start, uint64_t len,
 266                           CURLAIOCB *acb)
 267 {
 268     int i;
 269     uint64_t end = start + len;
 270     uint64_t clamped_end = MIN(end, s->len);
 271     uint64_t clamped_len = clamped_end - start;
 272
 273     for (i=0; i<CURL_NUM_STATES; i++) {
 274         CURLState *state = &s->states[i];
 275         uint64_t buf_end = (state->buf_start + state->buf_off);
 276         uint64_t buf_fend = (state->buf_start + state->buf_len);
 277
 278         if (!state->orig_buf)
 279             continue;
 280         if (!state->buf_off)
 281             continue;
 282
 283         // Does the existing buffer cover our section?
 284         if ((start >= state->buf_start) &&
 285             (start <= buf_end) &&
 286             (clamped_end >= state->buf_start) &&
 287             (clamped_end <= buf_end))
 288         {
 289             char *buf = state->orig_buf + (start - state->buf_start);
 290
 291             qemu_iovec_from_buf(acb->qiov, 0, buf, clamped_len);
 292             if (clamped_len < len) {
 293                 qemu_iovec_memset(acb->qiov, clamped_len, 0, len - clamped_len);
 294             }
 295             acb->ret = 0;
 296             return true;
 297         }
 298
 299         // Wait for unfinished chunks
 300         if (state->in_use &&
 301             (start >= state->buf_start) &&
 302             (start <= buf_fend) &&
 303             (clamped_end >= state->buf_start) &&
 304             (clamped_end <= buf_fend))
 305         {
 306             int j;
 307
 308             acb->start = start - state->buf_start;
 309             acb->end = acb->start + clamped_len;
 310
 311             for (j=0; j<CURL_NUM_ACB; j++) {
 312                 if (!state->acb[j]) {
 313                     state->acb[j] = acb;
 314                     return true;
 315                 }
 316             }
 317         }
 318     }
 319
 320     return false;
 321 }
 322
 323 /* Called with s->mutex held.  */
 324 static void curl_multi_check_completion(BDRVCURLState *s)
 325 {
 326     int msgs_in_queue;
 327
 328     /* Try to find done transfers, so we can free the easy
 329      * handle again. */
 330     for (;;) {
 331         CURLMsg *msg;
 332         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
 333
 334         /* Quit when there are no more completions */
 335         if (!msg)
 336             break;
 337
 338         if (msg->msg == CURLMSG_DONE) {
 339             int i;
 340             CURLState *state = NULL;
 341             bool error = msg->data.result != CURLE_OK;
 342
 343             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
 344                               (char **)&state);
 345
 346             if (error) {
 347                 static int errcount = 100;
 348
 349                 /* Don't lose the original error message from curl, since
 350                  * it contains extra data.
 351                  */
 352                 if (errcount > 0) {
 353                     error_report("curl: %s", state->errmsg);
 354                     if (--errcount == 0) {
 355                         error_report("curl: further errors suppressed");
 356                     }
 357                 }
 358             }
 359
 360             for (i = 0; i < CURL_NUM_ACB; i++) {
 361                 CURLAIOCB *acb = state->acb[i];
 362
 363                 if (acb == NULL) {
 364                     continue;
 365                 }
 366
 367                 if (!error) {
 368                     /* Assert that we have read all data */
 369                     assert(state->buf_off >= acb->end);
 370
 371                     qemu_iovec_from_buf(acb->qiov, 0,
 372                                         state->orig_buf + acb->start,
 373                                         acb->end - acb->start);
 374
 375                     if (acb->end - acb->start < acb->bytes) {
 376                         size_t offset = acb->end - acb->start;
 377                         qemu_iovec_memset(acb->qiov, offset, 0,
 378                                           acb->bytes - offset);
 379                     }
 380                 }
 381
 382                 acb->ret = error ? -EIO : 0;
 383                 state->acb[i] = NULL;
 384                 qemu_mutex_unlock(&s->mutex);
 385                 aio_co_wake(acb->co);
 386                 qemu_mutex_lock(&s->mutex);
 387             }
 388
 389             curl_clean_state(state);
 390             break;
 391         }
 392     }
 393 }
 394
 395 /* Called with s->mutex held.  */
 396 static void curl_multi_do_locked(CURLSocket *socket)
 397 {
 398     BDRVCURLState *s = socket->s;
 399     int running;
 400     int r;
 401
 402     if (!s->multi) {
 403         return;
 404     }
 405
 406     do {
 407         r = curl_multi_socket_action(s->multi, socket->fd, 0, &running);
 408     } while (r == CURLM_CALL_MULTI_PERFORM);
 409 }
 410
 411 static void curl_multi_do(void *arg)
 412 {
 413     CURLSocket *socket = arg;
 414     BDRVCURLState *s = socket->s;
 415
 416     qemu_mutex_lock(&s->mutex);
 417     curl_multi_do_locked(socket);
 418     curl_multi_check_completion(s);
 419     qemu_mutex_unlock(&s->mutex);
 420 }
 421
 422 static void curl_multi_timeout_do(void *arg)
 423 {
 424     BDRVCURLState *s = (BDRVCURLState *)arg;
 425     int running;
 426
 427     if (!s->multi) {
 428         return;
 429     }
 430
 431     qemu_mutex_lock(&s->mutex);
 432     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 433
 434     curl_multi_check_completion(s);
 435     qemu_mutex_unlock(&s->mutex);
 436 }
 437
 438 /* Called with s->mutex held.  */
 439 static CURLState *curl_find_state(BDRVCURLState *s)
 440 {
 441     CURLState *state = NULL;
 442     int i;
 443
 444     for (i = 0; i < CURL_NUM_STATES; i++) {
 445         if (!s->states[i].in_use) {
 446             state = &s->states[i];
 447             state->in_use = 1;
 448             break;
 449         }
 450     }
 451     return state;
 452 }
 453
 454 static int curl_init_state(BDRVCURLState *s, CURLState *state)
 455 {
 456     if (!state->curl) {
 457         state->curl = curl_easy_init();
 458         if (!state->curl) {
 459             return -EIO;
 460         }
 461         if (curl_easy_setopt(state->curl, CURLOPT_URL, s->url) ||
 462             curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
 463                              (long) s->sslverify) ||
 464             curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYHOST,
 465                              s->sslverify ? 2L : 0L)) {
 466             goto err;
 467         }
 468         if (s->cookie) {
 469             if (curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie)) {
 470                 goto err;
 471             }
 472         }
 473         if (curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, (long)s->timeout) ||
 474             curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
 475                              (void *)curl_read_cb) ||
 476             curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state) ||
 477             curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state) ||
 478             curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1) ||
 479             curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1) ||
 480             curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1) ||
 481             curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg) ||
 482             curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1)) {
 483             goto err;
 484         }
 485         if (s->username) {
 486             if (curl_easy_setopt(state->curl, CURLOPT_USERNAME, s->username)) {
 487                 goto err;
 488             }
 489         }
 490         if (s->password) {
 491             if (curl_easy_setopt(state->curl, CURLOPT_PASSWORD, s->password)) {
 492                 goto err;
 493             }
 494         }
 495         if (s->proxyusername) {
 496             if (curl_easy_setopt(state->curl,
 497                                  CURLOPT_PROXYUSERNAME, s->proxyusername)) {
 498                 goto err;
 499             }
 500         }
 501         if (s->proxypassword) {
 502             if (curl_easy_setopt(state->curl,
 503                                  CURLOPT_PROXYPASSWORD, s->proxypassword)) {
 504                 goto err;
 505             }
 506         }
 507
 508         /* Restrict supported protocols to avoid security issues in the more
 509          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
 510          * CVE-2013-0249.
 511          *
 512          * Restricting protocols is only supported from 7.19.4 upwards.
 513          */
 514 #if LIBCURL_VERSION_NUM >= 0x071304
 515         if (curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS) ||
 516             curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS)) {
 517             goto err;
 518         }
 519 #endif
 520
 521 #ifdef DEBUG_VERBOSE
 522         if (curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1)) {
 523             goto err;
 524         }
 525 #endif
 526     }
 527
 528     state->s = s;
 529
 530     return 0;
 531
 532 err:
 533     curl_easy_cleanup(state->curl);
 534     state->curl = NULL;
 535     return -EIO;
 536 }
 537
 538 /* Called with s->mutex held.  */
 539 static void curl_clean_state(CURLState *s)
 540 {
 541     int j;
 542     for (j = 0; j < CURL_NUM_ACB; j++) {
 543         assert(!s->acb[j]);
 544     }
 545
 546     if (s->s->multi)
 547         curl_multi_remove_handle(s->s->multi, s->curl);
 548
 549     s->in_use = 0;
 550
 551     qemu_co_enter_next(&s->s->free_state_waitq, &s->s->mutex);
 552 }
 553
 554 static void curl_parse_filename(const char *filename, QDict *options,
 555                                 Error **errp)
 556 {
 557     qdict_put_str(options, CURL_BLOCK_OPT_URL, filename);
 558 }
 559
 560 static void curl_detach_aio_context(BlockDriverState *bs)
 561 {
 562     BDRVCURLState *s = bs->opaque;
 563     int i;
 564
 565     WITH_QEMU_LOCK_GUARD(&s->mutex) {
 566         curl_drop_all_sockets(s->sockets);
 567         for (i = 0; i < CURL_NUM_STATES; i++) {
 568             if (s->states[i].in_use) {
 569                 curl_clean_state(&s->states[i]);
 570             }
 571             if (s->states[i].curl) {
 572                 curl_easy_cleanup(s->states[i].curl);
 573                 s->states[i].curl = NULL;
 574             }
 575             g_free(s->states[i].orig_buf);
 576             s->states[i].orig_buf = NULL;
 577         }
 578         if (s->multi) {
 579             curl_multi_cleanup(s->multi);
 580             s->multi = NULL;
 581         }
 582     }
 583
 584     timer_del(&s->timer);
 585 }
 586
 587 static void curl_attach_aio_context(BlockDriverState *bs,
 588                                     AioContext *new_context)
 589 {
 590     BDRVCURLState *s = bs->opaque;
 591
 592     aio_timer_init(new_context, &s->timer,
 593                    QEMU_CLOCK_REALTIME, SCALE_NS,
 594                    curl_multi_timeout_do, s);
 595
 596     assert(!s->multi);
 597     s->multi = curl_multi_init();
 598     s->aio_context = new_context;
 599     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
 600     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
 601     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
 602 }
 603
 604 static QemuOptsList runtime_opts = {
 605     .name = "curl",
 606     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 607     .desc = {
 608         {
 609             .name = CURL_BLOCK_OPT_URL,
 610             .type = QEMU_OPT_STRING,
 611             .help = "URL to open",
 612         },
 613         {
 614             .name = CURL_BLOCK_OPT_READAHEAD,
 615             .type = QEMU_OPT_SIZE,
 616             .help = "Readahead size",
 617         },
 618         {
 619             .name = CURL_BLOCK_OPT_SSLVERIFY,
 620             .type = QEMU_OPT_BOOL,
 621             .help = "Verify SSL certificate"
 622         },
 623         {
 624             .name = CURL_BLOCK_OPT_TIMEOUT,
 625             .type = QEMU_OPT_NUMBER,
 626             .help = "Curl timeout"
 627         },
 628         {
 629             .name = CURL_BLOCK_OPT_COOKIE,
 630             .type = QEMU_OPT_STRING,
 631             .help = "Pass the cookie or list of cookies with each request"
 632         },
 633         {
 634             .name = CURL_BLOCK_OPT_COOKIE_SECRET,
 635             .type = QEMU_OPT_STRING,
 636             .help = "ID of secret used as cookie passed with each request"
 637         },
 638         {
 639             .name = CURL_BLOCK_OPT_USERNAME,
 640             .type = QEMU_OPT_STRING,
 641             .help = "Username for HTTP auth"
 642         },
 643         {
 644             .name = CURL_BLOCK_OPT_PASSWORD_SECRET,
 645             .type = QEMU_OPT_STRING,
 646             .help = "ID of secret used as password for HTTP auth",
 647         },
 648         {
 649             .name = CURL_BLOCK_OPT_PROXY_USERNAME,
 650             .type = QEMU_OPT_STRING,
 651             .help = "Username for HTTP proxy auth"
 652         },
 653         {
 654             .name = CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
 655             .type = QEMU_OPT_STRING,
 656             .help = "ID of secret used as password for HTTP proxy auth",
 657         },
 658         { /* end of list */ }
 659     },
 660 };
 661
 662
 663 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
 664                      Error **errp)
 665 {
 666     BDRVCURLState *s = bs->opaque;
 667     CURLState *state = NULL;
 668     QemuOpts *opts;
 669     const char *file;
 670     const char *cookie;
 671     const char *cookie_secret;
 672     double d;
 673     const char *secretid;
 674     const char *protocol_delimiter;
 675     int ret;
 676
 677     ret = bdrv_apply_auto_read_only(bs, "curl driver does not support writes",
 678                                     errp);
 679     if (ret < 0) {
 680         return ret;
 681     }
 682
 683     if (!libcurl_initialized) {
 684         ret = curl_global_init(CURL_GLOBAL_ALL);
 685         if (ret) {
 686             error_setg(errp, "libcurl initialization failed with %d", ret);
 687             return -EIO;
 688         }
 689         libcurl_initialized = true;
 690     }
 691
 692     qemu_mutex_init(&s->mutex);
 693     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 694     if (!qemu_opts_absorb_qdict(opts, options, errp)) {
 695         goto out_noclean;
 696     }
 697
 698     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
 699                                           CURL_BLOCK_OPT_READAHEAD_DEFAULT);
 700     if ((s->readahead_size & 0x1ff) != 0) {
 701         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
 702                    s->readahead_size);
 703         goto out_noclean;
 704     }
 705
 706     s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT,
 707                                      CURL_BLOCK_OPT_TIMEOUT_DEFAULT);
 708     if (s->timeout > CURL_TIMEOUT_MAX) {
 709         error_setg(errp, "timeout parameter is too large or negative");
 710         goto out_noclean;
 711     }
 712
 713     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY,
 714                                      CURL_BLOCK_OPT_SSLVERIFY_DEFAULT);
 715
 716     cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
 717     cookie_secret = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE_SECRET);
 718
 719     if (cookie && cookie_secret) {
 720         error_setg(errp,
 721                    "curl driver cannot handle both cookie and cookie secret");
 722         goto out_noclean;
 723     }
 724
 725     if (cookie_secret) {
 726         s->cookie = qcrypto_secret_lookup_as_utf8(cookie_secret, errp);
 727         if (!s->cookie) {
 728             goto out_noclean;
 729         }
 730     } else {
 731         s->cookie = g_strdup(cookie);
 732     }
 733
 734     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
 735     if (file == NULL) {
 736         error_setg(errp, "curl block driver requires an 'url' option");
 737         goto out_noclean;
 738     }
 739
 740     if (!strstart(file, bs->drv->protocol_name, &protocol_delimiter) ||
 741         !strstart(protocol_delimiter, "://", NULL))
 742     {
 743         error_setg(errp, "%s curl driver cannot handle the URL '%s' (does not "
 744                    "start with '%s://')", bs->drv->protocol_name, file,
 745                    bs->drv->protocol_name);
 746         goto out_noclean;
 747     }
 748
 749     s->username = g_strdup(qemu_opt_get(opts, CURL_BLOCK_OPT_USERNAME));
 750     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PASSWORD_SECRET);
 751
 752     if (secretid) {
 753         s->password = qcrypto_secret_lookup_as_utf8(secretid, errp);
 754         if (!s->password) {
 755             goto out_noclean;
 756         }
 757     }
 758
 759     s->proxyusername = g_strdup(
 760         qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_USERNAME));
 761     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET);
 762     if (secretid) {
 763         s->proxypassword = qcrypto_secret_lookup_as_utf8(secretid, errp);
 764         if (!s->proxypassword) {
 765             goto out_noclean;
 766         }
 767     }
 768
 769     trace_curl_open(file);
 770     qemu_co_queue_init(&s->free_state_waitq);
 771     s->aio_context = bdrv_get_aio_context(bs);
 772     s->url = g_strdup(file);
 773     s->sockets = g_hash_table_new_full(NULL, NULL, NULL, g_free);
 774     qemu_mutex_lock(&s->mutex);
 775     state = curl_find_state(s);
 776     qemu_mutex_unlock(&s->mutex);
 777     if (!state) {
 778         goto out_noclean;
 779     }
 780
 781     // Get file size
 782
 783     if (curl_init_state(s, state) < 0) {
 784         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 785                 "curl library initialization failed.");
 786         goto out;
 787     }
 788
 789     s->accept_range = false;
 790     if (curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1) ||
 791         curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION, curl_header_cb) ||
 792         curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s)) {
 793         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 794                 "curl library initialization failed.");
 795         goto out;
 796     }
 797     if (curl_easy_perform(state->curl))
 798         goto out;
 799     if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d)) {
 800         goto out;
 801     }
 802     /* Prior CURL 7.19.4 return value of 0 could mean that the file size is not
 803      * know or the size is zero. From 7.19.4 CURL returns -1 if size is not
 804      * known and zero if it is really zero-length file. */
 805 #if LIBCURL_VERSION_NUM >= 0x071304
 806     if (d < 0) {
 807         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 808                 "Server didn't report file size.");
 809         goto out;
 810     }
 811 #else
 812     if (d <= 0) {
 813         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 814                 "Unknown file size or zero-length file.");
 815         goto out;
 816     }
 817 #endif
 818
 819     s->len = d;
 820
 821     if ((!strncasecmp(s->url, "http://", strlen("http://"))
 822         || !strncasecmp(s->url, "https://", strlen("https://")))
 823         && !s->accept_range) {
 824         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 825                 "Server does not support 'range' (byte ranges).");
 826         goto out;
 827     }
 828     trace_curl_open_size(s->len);
 829
 830     qemu_mutex_lock(&s->mutex);
 831     curl_clean_state(state);
 832     qemu_mutex_unlock(&s->mutex);
 833     curl_easy_cleanup(state->curl);
 834     state->curl = NULL;
 835
 836     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
 837
 838     qemu_opts_del(opts);
 839     return 0;
 840
 841 out:
 842     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
 843     curl_easy_cleanup(state->curl);
 844     state->curl = NULL;
 845 out_noclean:
 846     qemu_mutex_destroy(&s->mutex);
 847     g_free(s->cookie);
 848     g_free(s->url);
 849     g_free(s->username);
 850     g_free(s->proxyusername);
 851     g_free(s->proxypassword);
 852     curl_drop_all_sockets(s->sockets);
 853     g_hash_table_destroy(s->sockets);
 854     qemu_opts_del(opts);
 855     return -EINVAL;
 856 }
 857
 858 static void curl_setup_preadv(BlockDriverState *bs, CURLAIOCB *acb)
 859 {
 860     CURLState *state;
 861     int running;
 862
 863     BDRVCURLState *s = bs->opaque;
 864
 865     uint64_t start = acb->offset;
 866     uint64_t end;
 867
 868     qemu_mutex_lock(&s->mutex);
 869
 870     // In case we have the requested data already (e.g. read-ahead),
 871     // we can just call the callback and be done.
 872     if (curl_find_buf(s, start, acb->bytes, acb)) {
 873         goto out;
 874     }
 875
 876     // No cache found, so let's start a new request
 877     for (;;) {
 878         state = curl_find_state(s);
 879         if (state) {
 880             break;
 881         }
 882         qemu_co_queue_wait(&s->free_state_waitq, &s->mutex);
 883     }
 884
 885     if (curl_init_state(s, state) < 0) {
 886         curl_clean_state(state);
 887         acb->ret = -EIO;
 888         goto out;
 889     }
 890
 891     acb->start = 0;
 892     acb->end = MIN(acb->bytes, s->len - start);
 893
 894     state->buf_off = 0;
 895     g_free(state->orig_buf);
 896     state->buf_start = start;
 897     state->buf_len = MIN(acb->end + s->readahead_size, s->len - start);
 898     end = start + state->buf_len - 1;
 899     state->orig_buf = g_try_malloc(state->buf_len);
 900     if (state->buf_len && state->orig_buf == NULL) {
 901         curl_clean_state(state);
 902         acb->ret = -ENOMEM;
 903         goto out;
 904     }
 905     state->acb[0] = acb;
 906
 907     snprintf(state->range, 127, "%" PRIu64 "-%" PRIu64, start, end);
 908     trace_curl_setup_preadv(acb->bytes, start, state->range);
 909     if (curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range) ||
 910         curl_multi_add_handle(s->multi, state->curl) != CURLM_OK) {
 911         state->acb[0] = NULL;
 912         acb->ret = -EIO;
 913
 914         curl_clean_state(state);
 915         goto out;
 916     }
 917
 918     /* Tell curl it needs to kick things off */
 919     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 920
 921 out:
 922     qemu_mutex_unlock(&s->mutex);
 923 }
 924
 925 static int coroutine_fn curl_co_preadv(BlockDriverState *bs,
 926         int64_t offset, int64_t bytes, QEMUIOVector *qiov,
 927         BdrvRequestFlags flags)
 928 {
 929     CURLAIOCB acb = {
 930         .co = qemu_coroutine_self(),
 931         .ret = -EINPROGRESS,
 932         .qiov = qiov,
 933         .offset = offset,
 934         .bytes = bytes
 935     };
 936
 937     curl_setup_preadv(bs, &acb);
 938     while (acb.ret == -EINPROGRESS) {
 939         qemu_coroutine_yield();
 940     }
 941     return acb.ret;
 942 }
 943
 944 static void curl_close(BlockDriverState *bs)
 945 {
 946     BDRVCURLState *s = bs->opaque;
 947
 948     trace_curl_close();
 949     curl_detach_aio_context(bs);
 950     qemu_mutex_destroy(&s->mutex);
 951
 952     g_hash_table_destroy(s->sockets);
 953     g_free(s->cookie);
 954     g_free(s->url);
 955     g_free(s->username);
 956     g_free(s->proxyusername);
 957     g_free(s->proxypassword);
 958 }
 959
 960 static int64_t curl_getlength(BlockDriverState *bs)
 961 {
 962     BDRVCURLState *s = bs->opaque;
 963     return s->len;
 964 }
 965
 966 static void curl_refresh_filename(BlockDriverState *bs)
 967 {
 968     BDRVCURLState *s = bs->opaque;
 969
 970     /* "readahead" and "timeout" do not change the guest-visible data,
 971      * so ignore them */
 972     if (s->sslverify != CURL_BLOCK_OPT_SSLVERIFY_DEFAULT ||
 973         s->cookie || s->username || s->password || s->proxyusername ||
 974         s->proxypassword)
 975     {
 976         return;
 977     }
 978
 979     pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), s->url);
 980 }
 981
 982
 983 static const char *const curl_strong_runtime_opts[] = {
 984     CURL_BLOCK_OPT_URL,
 985     CURL_BLOCK_OPT_SSLVERIFY,
 986     CURL_BLOCK_OPT_COOKIE,
 987     CURL_BLOCK_OPT_COOKIE_SECRET,
 988     CURL_BLOCK_OPT_USERNAME,
 989     CURL_BLOCK_OPT_PASSWORD_SECRET,
 990     CURL_BLOCK_OPT_PROXY_USERNAME,
 991     CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
 992
 993     NULL
 994 };
 995
 996 static BlockDriver bdrv_http = {
 997     .format_name                = "http",
 998     .protocol_name              = "http",
 999
1000     .instance_size              = sizeof(BDRVCURLState),
1001     .bdrv_parse_filename        = curl_parse_filename,
1002     .bdrv_file_open             = curl_open,
1003     .bdrv_close                 = curl_close,
1004     .bdrv_getlength             = curl_getlength,
1005
1006     .bdrv_co_preadv             = curl_co_preadv,
1007
1008     .bdrv_detach_aio_context    = curl_detach_aio_context,
1009     .bdrv_attach_aio_context    = curl_attach_aio_context,
1010
1011     .bdrv_refresh_filename      = curl_refresh_filename,
1012     .strong_runtime_opts        = curl_strong_runtime_opts,
1013 };
1014
1015 static BlockDriver bdrv_https = {
1016     .format_name                = "https",
1017     .protocol_name              = "https",
1018
1019     .instance_size              = sizeof(BDRVCURLState),
1020     .bdrv_parse_filename        = curl_parse_filename,
1021     .bdrv_file_open             = curl_open,
1022     .bdrv_close                 = curl_close,
1023     .bdrv_getlength             = curl_getlength,
1024
1025     .bdrv_co_preadv             = curl_co_preadv,
1026
1027     .bdrv_detach_aio_context    = curl_detach_aio_context,
1028     .bdrv_attach_aio_context    = curl_attach_aio_context,
1029
1030     .bdrv_refresh_filename      = curl_refresh_filename,
1031     .strong_runtime_opts        = curl_strong_runtime_opts,
1032 };
1033
1034 static BlockDriver bdrv_ftp = {
1035     .format_name                = "ftp",
1036     .protocol_name              = "ftp",
1037
1038     .instance_size              = sizeof(BDRVCURLState),
1039     .bdrv_parse_filename        = curl_parse_filename,
1040     .bdrv_file_open             = curl_open,
1041     .bdrv_close                 = curl_close,
1042     .bdrv_getlength             = curl_getlength,
1043
1044     .bdrv_co_preadv             = curl_co_preadv,
1045
1046     .bdrv_detach_aio_context    = curl_detach_aio_context,
1047     .bdrv_attach_aio_context    = curl_attach_aio_context,
1048
1049     .bdrv_refresh_filename      = curl_refresh_filename,
1050     .strong_runtime_opts        = curl_strong_runtime_opts,
1051 };
1052
1053 static BlockDriver bdrv_ftps = {
1054     .format_name                = "ftps",
1055     .protocol_name              = "ftps",
1056
1057     .instance_size              = sizeof(BDRVCURLState),
1058     .bdrv_parse_filename        = curl_parse_filename,
1059     .bdrv_file_open             = curl_open,
1060     .bdrv_close                 = curl_close,
1061     .bdrv_getlength             = curl_getlength,
1062
1063     .bdrv_co_preadv             = curl_co_preadv,
1064
1065     .bdrv_detach_aio_context    = curl_detach_aio_context,
1066     .bdrv_attach_aio_context    = curl_attach_aio_context,
1067
1068     .bdrv_refresh_filename      = curl_refresh_filename,
1069     .strong_runtime_opts        = curl_strong_runtime_opts,
1070 };
1071
1072 static void curl_block_init(void)
1073 {
1074     bdrv_register(&bdrv_http);
1075     bdrv_register(&bdrv_https);
1076     bdrv_register(&bdrv_ftp);
1077     bdrv_register(&bdrv_ftps);
1078 }
1079
1080 block_init(curl_block_init);